Many easterners don't understand how western water rights work. Just because you have water on your land, it usually moves to somewhere else in a creek or river. Someone downstream might have filed a right for that water. The rule is 1st in right gets the water. If there are more rights filed than there is water to fill them, the senior, or earliest, rights get their full amount before anyone else gets any. In water short years like this one, the junior rights might not get any at all. It's not divvied up, it's all or none. You might not like that rule but it was initially set up that way and the laws still exist. Changing it now would disrupt the entire western water supply system.
We had a discussion a while back about people in OR not being able to catch rainwater off their roofs in barrels for watering. To a westerner familiar with water rights, it's very understandable. That roof water will run off into a stream and someone downstream has a right to all water in the watershed. If you catch the water, it won't make it to the stream and you're depriving someone with a senior right of his water.
There's a ski area near here that would love to develop a new run. However, the land where the run would be doesn't get enough natural snow so they'd have to pump water from a creek near the current lifts to make snow. Sounds simple, right? Not so. A rancher down below has the rights on water in the creek. They can use it to make snow where it is as it will still be in the creek when it melts. The new run, however, would require the water to be pumped over a ridge. When it melted, it would go down a different creek and the rancher wouldn't get it. So, he refuses to allow the ski resort to use it as he would lose it. He has the rights, he gets the water.
There are some seemingly exceptions to the rights laws, but not really. An irrigation district can own the rights and sell shares to land owners. The district determines how much water a share will receive each year. My place is under the Twin Falls Canal Company. Generally, you own 1 share/acre and it entitles you to 1 acre foot per share. That's enough water to cover the acre a foot deep during the irrigation season. During a dry year, the Canal Co can reduce the amount of water per share if there isn't enough. This isn't an exception as the Canal Co holds the rights, not the individual land owner. The Company still get it's water under state law and it can divide it up among shareholders at it sees fit.
